The present invention relates to a cigarette checking apparatus, particularly suited for location at the output of a filter assembly machine
The cigarettes coming off a filter assembly machine are usually supplied to a packing machine on a conveyor belt on which they are stacked in a substantially uniform layer crosswise in relation to the traveling direction.
At the output of the filter assembly machine, the cigarettes are subjected to a series of checks to determine given geometrical and physical characteristics, such as length, diameter, ventilation, weight, firmness, etc. Should the results of said checks fail to conform with given reference data, they are interpreted by the operator for making appropriate adjustments, for example, to the cutters on the manufacturing and filter assembly machines, to the printing means, to the number of holes formed by the filter perforating means, etc. Correct interpretation of the data supplied by the checking devices naturally depends on correct interpretation of the faults detected during inspection. The problem of interpreting inspection data relative to cigarettes produced on single and, particularly, dual rod cigarette manufacturing machines, is solved by the cigarette sampling unit described in Italian Patent Application N.3386A/88 of Mar. 21, 1988 filed by the present Applicant and the content of which is included herein purely by way of reference as required. Said unit provides for selectively withdrawing cigarettes from a given location on the filter assembly machine, so that the exact origin of the sampled cigarette and the positions occupied by the same between the filter assembly machine and the input of the checking device are known.
A known checking device consists of a series of units arranged one on top of the other. Inside said device, each sample cigarette is fed downwards from one unit to the next, each of which provides for checking a given characteristic.
The time taken to check each cigarette therefore equals the total operating time of the various units, which is fairly lengthy. Moreover, no provision is made on said device for repeat checking a given characteristic to the exclusion of the others. A further point to note is that, should said device comprise a firmness testing unit, the cigarettes are usually subjected to destructive testing and consequently rejected.